Programmable memories are useful with logic circuits to institute or control certain functions by control circuits. The number and type of functions that might be controlled are almost limitless.
For instance such functions might include automatic telephone dialing, charging the cost of the call to a particular account, controlling access through entry doors such as into hotel rooms, personal identification of the card holder, supplying tamper-proof information, starting and/or stopping and/or varying the operation of a machine, inducing the taking of certain measurements serving as a supplemental memory, as to modify a fixed memory such as used by a microprocessor and microcomputer, in a control or logic system to provide user modification of performance, and a myriad of other functions.
Previously programmable memories have been, by and large, extremely sophisticated devices. Some are programmable electronically; some are programmable by soldering and welding certain wires and parts or by plugging in conductors for electrical components; some have required assembly of circuit cards on other circuit cards; and some must be programmed during original manufacture.
Among the prior U.S. patents which disclose a number of such memory devices are Brownfield U.S. Pat. No. 3,038,105; Stapper, Jr. U.S. Pat. No. 3,157,857; Cannon U.S. Pat. No. 3,373,406; Garcia U.S. Pat. No. 3,393,449; David U.S. Pat. No. 3,428,954; Lee U.S. Pat. No. 3,492,659; Wallace U.S. Pat. No. 3,504,132; Wallace U.S. Pat. No. 3,560,941; Koo U.S. Pat. No. 3,582,908; Groeger U.S. Pat. No. 3,599,183; Mosman U.S. Pat. No. 3,631,536; and Kohler et al U.S. Pat. No. 3,653,006.